Manufacturers

Astrophotography

If
you have Digital SLR, you can take some beautiful wide-field images
with just the camera on a tripod. This is where I would suggest you
start if you are just getting into astrophotography with a DSLR.

Next,
you may want to shoot some images with your camera and lens mounted
piggyback on your telescope. You will need an equatorially mounted
telescope (not an altazimuth mount) to take pictures longer than about
30 seconds.

Once you've got some experience, you may want to hook
your DSLR up to shoot through your telescope. In this case, the scope
takes the place of the camera lens. You will need some accessories to
use it like this to shoot astrophotos. At a minimum, you will need a
T-mount and adapter.

T-Mount and 2-Inch Adapter

T-Mount and 2 Inch Adapter If
your telescope has a 2 inch focuser, you will need a T-Mount ($20) and
2-inch Adapter ($30). The T-mount has a bayonet flange that mounts to
your specific type of camera, such as Nikon or Canon. The 2-inch
adapter screws into the T-mount. The 2-inch adapter then goes into the
2-inch focuser on your telescope.

Not every telescope has a 2-inch focuser. A 1.25 inch focuser and adapter will probably vignette on a DSLR.

Remote Release for Long Exposures

The
T-mount and adapter are all you really need to get started shooting
through your telescope. You can simply use the camera's self timer to
open the shutter for exposures up to 30 seconds. This will work much
better than trying to press the shutter button with your finger as this
will probably move the telescope and blur the picture.

For
exposures longer than 30 seconds, you need to set the camera to the
"bulb" setting, usually the next shutter speed that comes up on the
camera after 30 seconds. The bulb setting holds the shutter open as
long as you hold down the shutter release. This can be a serious
problem because there is no way you can do this with your finger and
not move the telescope during a long exposure. So you will need some
type of remote release such as a wired remote. These usually plug into
the side of the camera.

Some cameras, such as Canon's Digital
Rebel series (300D, 350D, 400D) use a simple mini stereo plug for the
bulb release. You can even make one of these yourself very
inexpensively. Some Nikon cameras use an infra-red remote release. Most
advanced amateur and professional digital cameras, such as Canon's 1D,
20D and 30D, and use a proprietary N3 plug. You will have to purchase a
cable from the camera manufacturer for this type of plug.

Once you have the correct kind of bulb-exposure cable, you can start taking long-exposure astrophotos.